“What is the meaning of our life if we [are] destroying the planet while sacrificing the future of our children?” the French president asked. “Let us face it. There is no planet B.”

Emmanuel Macron conceded he had probably failed in his attempt during a three-day trip to Washington to persuade Donald Trump to stay in the Iran nuclear deal, describing US flip-flopping on international agreements as “insane,” reports today's Guardian.

The French president had hoped to convince Trump to continue to waive sanctions on Iran, as agreed by the 2015 nuclear deal, in which Iran agreed to accept strict curbs on its nuclear activities. Macron offered Trump the prospect of negotiations on a new complementary deal that would address Iranian missile development and Tehran’s military intervention in the Middle East.

But speaking to US reporters before leaving Washington, Macron said: “My view – I don’t know what your president will decide – is that he will get rid of this deal on his own, for domestic reasons.”

Noting that Trump had also pulled the US out of the Paris climate change accord – another commitment of the Obama administration – Macron said such frequent changes in the US position on global issues “can work in the short term but it’s very insane in the medium to long term”.

The admissions come after a day of intimate fraternity with Trump, during which Macron made an impassioned speech in Washington advocating many of the things Trump has spent much of his presidency trying to destroy.